TAF pickup

[Lukenatme]

Nice pick up--cosmetically, it looks a lot like mine that I found in the back of a seldom-visited antique mall here in town. My Thing hand magnet wouldn't pick up the ball, but now it works great.

The reason why my girlfriend and I like it so much is that it's easy to learn what you need to do to progress through the game, but difficult to master. All the things you have to do also mesh well with the theme and make sense. Maybe there are hundreds of other pins that do just that, but I'm happy with this one. We're both HUGE fans of the Simpsons and I just assumed we would trade this for a TSPP, but we played that last summer and it just didn't click with us--at least not enough to trade TAF for it.

 

[stangbat]

elfyhead, first we need to verify that the 12v is actually low. If you read GameMcGame's Jurassic Park thread, you'll see that I was trying to figure out why a -98v line was low. Turns out that it was because it was actually unloaded and the DMD was not using this voltage. Once I put a 10k ohm resistor between the -110v and -98v lines to induce a load on the -98v, the -98v came up just fine.

Also, if the 12v is actually low and is the problem, a HV rebuild won't help you. You'll need to find the culprit on the 12v section of the PS, not the HV section.

 

[elfyhead]

elfyhead, first we need to verify that the 12v is actually low. If you read GameMcGame's Jurassic Park thread, you'll see that I was trying to figure out why a -98v line was low. Turns out that it was because it was actually unloaded and the DMD was not using this voltage. Once I put a 10k ohm resistor between the -110v and -98v lines to induce a load on the -98v, the -98v came up just fine.

Also, if the 12v is actually low and is the problem, a HV rebuild won't help you. You'll need to find the culprit on the 12v section of the PS, not the HV section.

yeah, i was reading pinrepair.com again, and i need to make the measurement of the +12V with the DMD disconnected, and at the driver board itself, to check that one. i'm going to do that tonight.

 

[elfyhead]

Get this for $5-

http://www.greatplainselectronics.com/proddetail.asp?prod=WPC-HVP-KIT

Out of Stock :/...

 

[stangbat]

Out of Stock :/...

I don't think you need to worry, your high voltage readings seem fine.

 

[cal50]

Out of Stock :/...

...add one or two to your next parts order. Its cheap and easy to do and when I shop my games I re-build the HV sections and the standard things to the power driver boards while I have it apart. I prefer to get the machine 100% running and reliable before tearing it down for shopping.

 

[elfyhead]

unhooked the DMD and took some readings of voltages on the DMD controller board.

at J604, the readings are the same. what is supposed to be +12V (at pin 7) is about +6.5V.

*but*, at J606, where the power comes in from the driver board (at pins 6 & 7), the voltage is +14.3V.

so the driver board +12V section seems OK. the only things i see on the DMD controller board between J606 and J604 in the +12V line are a diode (D7) and a resistor (R24). i'll be checking those later tonight (dinner first ).

 

[elfyhead]

OK - the resistor is actually R7 on my board (R24 is for WPC-95).

see the attached image for the right part of the circuit.

at point A, as labelled on the attachment, the voltage is +13.5V. at point B, it's +6.6V.

R7 measures as 55 ohms, so that's not the problem.

i'm wondering if the zener diode at D8 is bad? would that limit the voltage on the other side of R7 to 6.6V instead of 12V?

and, while measuring all the resistors on the board, i found that R8 (the big ceramic, 5W, 4.7k ohm) was bad. i have no idea how that could affect the +12V part of the circuit, *or* why the high voltages would be fine with it like that, but it's definitely dead.

 

[elfyhead]

i'm wondering if the zener diode at D8 is bad? would that limit the voltage on the other side of R7 to 6.6V instead of 12V?

and, while measuring all the resistors on the board, i found that R8 (the big ceramic, 5W, 4.7k ohm) was bad. i have no idea how that could affect the +12V part of the circuit, *or* why the high voltages would be fine with it like that, but it's definitely dead.

got my parts from GPE last night, replaced R8 and D8, and, voila! nice working DMD. and a spare brand new vishay one as well (since the old one that the guy gave me with the purchase works just fine) .

now, on to the next thing. one of the battery holders has a broken clip on one end. while i'm messing with it, i'll probably just move it off the board. is the standard thing to do just to put it on the side of the backbox and run wires to the board?

 

[webfart]

Would you sell the spare DMD? If so, how much?

 

[cal50]

got my parts from GPE last night, replaced R8 and D8, and, voila! nice working DMD. and a spare brand new vishay one as well (since the old one that the guy gave me with the purchase works just fine) .

now, on to the next thing. one of the battery holders has a broken clip on one end. while i'm messing with it, i'll probably just move it off the board. is the standard thing to do just to put it on the side of the backbox and run wires to the board?

Glad you got your display working.
I put my remote battery pack off the board on the side of the head box. I used a 3 cell plastic holder and a standard CPU fan cable extender for the wiring. The cable extender has a male & female plug ends so you can un-plug your battery pack if you want to remover the board. They usually have 3 wires but I pull out the yellow / extra wire. Cut it in the middle and solder the ends to the battery pack and the other end to your board.

http://www.newegg.com/Product/Produ...189006&cm_re=fan_cable-_-12-189-006-_-Product

 

[elfyhead]

Would you sell the spare DMD? If so, how much?

not just yet - want to be sure everything is working well. and in fact i want to try it in there and see how it compares to the old one.

so i remote mounted a battery pack tonight, following the descriptions at http://www.myhomegameroom.com/pinball/tech/remotebattery/index.htm and http://www.pinballnews.com/learn/battery.html

mounted it on the side of the header. i measured on the back of the MPU board and have +4.3 V across the two pins for the left-hand battery (i just soldered the wires on the existing battery holder), so it seems the voltage is getting there.

but it's not working - still does a factory reset every time i power it up (and loses settings, date/time, etc.).

what's the next thing to check? bad RAM? some other component? did i munge the remote mounting somehow?

ETA: just found the section on pinrepair.com on this. looks like i'll be checking power at the U8 RAM, then possibly the blocking diodes.

 

[elfyhead]

did i munge the remote mounting somehow?

it was this. i didn't realize it mattered which of the old battery holders you connected the new + and - to. the pictures at pinrepair.com showed it immediately.

so i fixed that, and it now works!

now on to the next thing to work on - several to choose from, but i think i'll fix up the lighting next. have a few insert lights and some flashers that new bulbs didn't fix...