Cheyenne with multi-exidy blank screen bars.

dethfactor

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Cheyenne with multi-exidy blank/screen bars.

So I had a working Cheyenne that I put the multi-exidy. Now I'm running a blank screen or yellow/blue jailbars. I checked the voltage and there's a huge drop across the board. not sure if this is normal. Anyone have advice or repair exidy boards? I'm mildly frustrated and at a loss.

Went back and fiddled with the dips as widel.com is down and had to use googles cache of the site.
Got a dip error then a nvram error and now back to bars.
fc7eef8c.jpg


Any help?
 
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Common problem on Exidy boards from what I can tell. I found a few threads and all the posted pics are of the same issue. I have a Crossbow board with the same problem as well.
 
Common problem on Exidy boards from what I can tell. I found a few threads and all the posted pics are of the same issue. I have a Crossbow board with the same problem as well.

Yeah, I've noticed a few threads as well but no definitive answer. I also noticed that the voltages were turned up pretty high on my cab. The switcher was turned up to 6.3-6.4v but was showing 5.2v across the 74xxx's on the boards. It was a pretty huge drop and not sure if it's normal. The -/+18v was running in the 21.2v range on both legs, not sure if this is normal but cheyenne ran.
 
I had another Crossbow board so I never troubleshot the one with the bars.
I guess I could get ambitious and look at it..
I re-built the PS so I know that isn't my problem.
 
What did you do to rebuild it? This thing is kinda trashed and some of the connectors skip that passthrough board. I'd like to rebuild the PSU and replace some of these connectors that are roasted.
 
I have some experience with these issues. One common failure with the Exidy multi board is either bars or the dreaded 'NVRAM error' screen. As you have indicated, this can be a voltage issue. If you check to see what your logic voltage is at the NVRAM socket, I bet you are below +5V there.

From what I have seen, a board that is functional without the kit can have voltage problems when a kit is installed. At this point, the extra connections to the new daughterboards can allow for another voltage drop, etc.

There are a few ways you can go about suring up your voltages. I would check for cold solder joints on the interconnect pins that connect the sound board to the logic board. These interconnects are available at pinball parts sites. Reseating/repinning the molex connectors coming from the power supply to the CPU board has also helped me.

A more extreme/permanent measure would be to run some jumper wires around to boost the +5V logic level in places. That is probably a safer bet than running the +5V too high on one end of the board in order for the appropriate amount to trickle down to the other end of the board.
 
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What did you do to rebuild it? This thing is kinda trashed and some of the connectors skip that passthrough board. I'd like to rebuild the PSU and replace some of these connectors that are roasted.

I replaced all the caps (had to get creative with a few), replaced all the diodes (a few were smoked) and an IC I believe. It's been a while.
I ordered a bunch of extra parts when doing mine and can kit something up for you. I don't have the caps, but I believe I have everything else. I'll check the manual and see what I have. If it's working though, just replacing the caps should do it. Crossbow doesn't have the filter board and I doubt it's needed. You could probably bypass all of the connectors.
 
I have some experience with these issues. One common failure with the Exidy multi board is either bars or the dreaded 'NVRAM error' screen. As you have indicated, this can be a voltage issue. If you check to see what your logic voltage is at the NVRAM socket, I bet you are below +5V there.

From what I have seen, a board that is functional without the kit can have voltage problems when a kit is installed. At this point, the extra connections to the new daughterboards can allow for another voltage drop, etc.

There are a few ways you can go about suring up your voltages. I would check for cold solder joints on the interconnect pins that connect the sound board to the logic board. These interconnects are available at pinball parts sites. Reseating/repinning the molex connectors coming from the power supply to the CPU board has also helped me.

A more extreme/permanent measure would be to run some jumper wires around to boost the +5V logic level in places. That is probably a safer bet than running the +5V too high on one end of the board in order for the appropriate amount to trickle down to the other end of the board.

What about a board with the bars without a kit?
Any idea what causes the bars?
 
I replaced all the caps (had to get creative with a few), replaced all the diodes (a few were smoked) and an IC I believe. It's been a while.
I ordered a bunch of extra parts when doing mine and can kit something up for you. I don't have the caps, but I believe I have everything else. I'll check the manual and see what I have. If it's working though, just replacing the caps should do it. Crossbow doesn't have the filter board and I doubt it's needed. You could probably bypass all of the connectors.

Sounds awesome. The game did work before the multi. Not sure why the passthrough is in there, but the lengths of some of the wire is a little short and sort of strenuous to the wire when the connectors are in the board, if I redo the connectors I'll probably use the bypass again to tidy up the joint and probably remove all the mouse/rat piss off of the cage. Apparently it was hoarding peanuts in the PSU. On a side note, You wouldn't happen to know where I can find the center pivot pin for the gun, the one that runs through the gun's swivel mount, control panel ring and the mounting knuckle? It's currently being proxied by two shitty bolts and the gun can spin 360 and flops around like a dead hooker.




What about a board with the bars without a kit?
Any idea what causes the bars?

Agreed, Once in awhile the game itself would give me weird ROM errors or I would get a sound power error. I even got the bars once in a while. I pulled/cleaned up the connectors/roms and it worked the other night 100% and I played it for a few hours. The following day it was acting up again. I figured the ROMS might've been going bad and so I installed the kit assuming that'd circumvent the problem.

I think there's definitely a few compounded issues. The voltage drop is something fierce across the logic PCB. (1-2vdc) Also the 18v lines on it were up to 21v. g3n, is this the same on your game? I believe there's some adjustment in the encased portion of the PSU outside the switcher, is that the 18v adjustment? But yeah, the switcher PSU was putting out 6.4vdc at the lugs and somewhere around 5.2vdc with the regular chips installed and 4.3vdc with the multi kit installed.

I'm considering having the board serviced by El Dorado and they recommended to change the interconnect pins between the logic/sound board as well. I also contacted Bob Roberts about getting new connectors and just redoing all the PCB pins and connectors as well.
 
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I was going to rebuild the linear P/S but as it was only doing the +5vdc, I did not think it was worth the time and effort so I swapped it out for a switcher.
The +22 and -22 come from the x-former, bridge rectifier and then the 7912 and 7812 take care of the step done on the sound PCB to -12vdc and +12vdc respectively.

Anyway, I was really hoping that you found a resolution to the "bars" issue as that is EXACTLY what I am getting now. The board was an unknown and does not have the Exidy kit installed yet.

I tested and have +5.05 vdc on pins 4,5,6,7 on the sound PCB connection so that's good.
I have the -12vdc and +12vdc through the 2 VR's so that's good.
As I am not familiar with the Exidy set, any help would be greatly appreciated.

BTW, does the gun have to be attached for the game to work?

Also, I tried to place the game in test by pressing the button during boot but still came up bars.

I do get a short music score each and every time it boots but only get the bars on the display..

Thanks
Jeff
 
I was going to rebuild the linear P/S but as it was only doing the +5vdc, I did not think it was worth the time and effort so I swapped it out for a switcher.
The +22 and -22 come from the x-former, bridge rectifier and then the 7912 and 7812 take care of the step done on the sound PCB to -12vdc and +12vdc respectively.

Anyway, I was really hoping that you found a resolution to the "bars" issue as that is EXACTLY what I am getting now. The board was an unknown and does not have the Exidy kit installed yet.

I tested and have +5.05 vdc on pins 4,5,6,7 on the sound PCB connection so that's good.
I have the -12vdc and +12vdc through the 2 VR's so that's good.
As I am not familiar with the Exidy set, any help would be greatly appreciated.

BTW, does the gun have to be attached for the game to work?

Also, I tried to place the game in test by pressing the button during boot but still came up bars.

I do get a short music score each and every time it boots but only get the bars on the display..

Thanks
Jeff

Sent the boards out over a month ago to El Dorado. Got a reply a last week saying my boards were next up in the queue. I'll post up what they say and if it works when I get 'em back.
 
Gun doesnt have to be hooked up for game to work.. bars on sxreen means rom problem.. ive seen them before..

by the way i buy broke exidy pcbs for 75.00 just incase you want to sell it
 
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Gun doesnt have to be hooked up for game to work.. bars on sxreen means rom problem.. ive seen them before..

by the way i buy broke exidy pcbs for 75.00 just incase you want to sell it


Thanks for the tip....

I'll be doing the re-seat thing this weekend and we'll see how it goes.

Jeff
 
Sent the boards out over a month ago to El Dorado. Got a reply a last week saying my boards were next up in the queue. I'll post up what they say and if it works when I get 'em back.

How much does El Dorado charge for repairs on these boards? I do not see them listed on the web site.

I have fixed several boards with this problem but it is never exactly the same thing that causes it. The 440 boards have problems distributing the +5v line. It will be good coming in but on the other side of the pcb or at the roms in this case it will be very low. This is why you see them with the switcher cranked up to over +6V sometimes or burn marks on the main power connector of the pcb. Many times it is bypass caps as mentioned earlier or just cracked or cold solder but it can also be a combination of things. I would check the voltage at the roms and ram to see if they match what is coming in the board and go from there.
 
OK,
Taking into consideration the age of the game and also that I wanted to take a little chance, I boosted the voltage at the connector to the PCB to +5.11vdc and read +5.06vdc at the ROMs.
The ROMs on my PCB set are those burned ROMs not EPROMs and they have little code numbers on them but I do not know if they are even in the right locations so that is next. I will try to find the key showing their locations and confirm them while I am doing the re-seat thing.
I cannot even get the game to go into test, which is a shame as I can use all the help I can get.
Jeff
 
UPDATE:

I confirmed that all the installed ROM's are in fact in the correct locations.

I have an empty socket, 1J on the sound PCB and several more, 6B, 7B, 8B, 10B and 11B on the CPU PCB. Can anyone confirm that this correct or is there missing IC's? I'll try and figure it out on the schems in the mean time.

On both PCB's, I checked all doides, transistors, resistor packs, VR's, and also made sure the electrolytic caps were not open or shorted.

I began reseating the ROM's by partially removing them then pressing them firmly back but noticed a couple of items which then made me take the long route and proceeded to pull, clean, straighten pins on ALL socketed IC's, EPROMs, ROMs, BPROMs, RAM and misc. Logic IC's - DAMM there's a lot of 6116's!

Found some really dirty EPROM legs some of which look like they were reprogrammed several times, (look beat). Found some bent legs and a really bad leg repair.

I will be firing this beast tonight and hope that my several hours of testing, repairs and housekeeping will pay off, otherwise the next step is a cap job....

BTW, who is Phil Mark?

Jeff
 
A little progress...

I installed the boardset and fired it up in test, start button closed and I got the "start-up" sound as before but now the displays bars, instead of just being a shade of blue, now appears to have all the colors scattered throughout, pixels of red , green and blue. I also got another audio byte, I do not remember exactly but it went something like, "you are all going to die".

So I did make a positive change, although a very small one.

Next I am going to cap the PCB set and see if it makes a difference.....

Jeff
 
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