G05-805 still no pic.

mrsodapop

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Hi All,
I didn't want to hijack the Battlezone post, so I made this (me too) post. I have the same problem as Jeff F.:
-Plays blind.
-Neck does glow.
-Spot killer is OFF.
-Brightness and contrast don't seem to do anything.
-Monitor PCB has been cap-kit'd and connections re-soldered.
-XY chatter can be heard from monitor.
I also installed BR cap/transistor kit in monitor, and all connection reflowed.

Monitor is 15" in an Asteroids cocktail. It is the original monitor, and it was DOA when I got it.
Someone mentioned mentioned checking 150v line, where do I find this point to check it? Any other ideas?
I do have a Battlezone, could I plug this monitor into it with out doing damage?
Thanks for any help
Aaron
 
Almost sounds to me like you are not getting the HV from the EHT unit.

Measure the voltages going to the P900 connector on the EHT cage. (you'll find anywhere from 90-400 volts there, so be sure to know which you are checking)

Were the solder joints redone on the EHT unit along with the deflection pcb ? (P900)
Was the EHT unit re-capped too ?
 
Hi,
The EHT board was recapped, connectors were reflowed. P900 test voltages: pin3 0vdc(spec. is 400vdc) pin5- 0vdc(spec. is 90vdc) pin8- 40vdc(spec. is 40vdc) pin7-ground (tested good). I looks like I am missing the 90v and 400v! Is my problem on the deflection PCB?
Thanks for any ideas
Aaron
 
Hi again,
Anybody have an idea on what to check next to find reason for the missing 400v and 90v at P900. I removed the EHT board and double checked solider points, and that the new caps are in correct. Also checked diodes, and they check good.
 
The +40 comes from the deflection board and feeds the EHT board. If you have the 40 volts then the problem is on the EHT board. Make sure you have the 40 volts at
C900 on the EHT board, If you don't the problem is in the connection from P900 coming from the deflection board. If you have the 40 volts at C900 then you need to go further into the circuit on the EHT. Have you checked the transistors? Q900, 901, 902, 903 on the EHT board?
 
I checked the trans. and 2 seem bad. I sent an order out to Mouser and decided to shot gun all 4. Will post back with results.
Thanks
Aaron
 
Ok ,I got the new transistors,R&R all 4 of them on the EHT. Monitor screen still blank. My new readings at P900 are: pin3 134vdc(spec. 400vdc) pin5 27vdc (spec. 90vdc) pin8 35vdc (spec.40vdc).
Before the transistors, I had a good 40vdc at at pin8 and 0vdc at all other points. I had also installed cap kit and re-soldered all connector pins(and any questionable pionts) previously.
Anybody have any ideas? This monitor is starting to drive me nuts!
Thanks for any help
Aaron
 
Ok ,I got the new transistors,R&R all 4 of them on the EHT. Monitor screen still blank. My new readings at P900 are: pin3 134vdc(spec. 400vdc) pin5 27vdc (spec. 90vdc) pin8 35vdc (spec.40vdc).
Before the transistors, I had a good 40vdc at at pin8 and 0vdc at all other points. I had also installed cap kit and re-soldered all connector pins(and any questionable pionts) previously.
Anybody have any ideas? This monitor is starting to drive me nuts!
Thanks for any help
Aaron

This is from the B&W vector FAQ:"90V measures less than 80V
Measure the voltage on the anode of the Zener diode ZD900 or the emitter of Q901. Should read
9V. If less, replace the diode.
 
I checked Emitter of Q901, and have 21vdc. Perhaps I should just replace all diodes and resistors, they are practically the only items left that have not been replaced(except for flyback).
"This is from the B&W vector FAQ:"90V measures less than 80V" --Do you have a diagnostic/trouble shoot chart?
If so could I get a copy?
Thanks for all your help so far
Aaron
 
Ok now I'm more confused?! Voltages good, but still no picture!
Lets replay what I have done so far --got an Asteroids cocktail from a friend for repair. Plays blind with a totally dead G05-805 monitor.
Installed Bob Roberts cap/trans. kit- monitor now powers up (neck glow, can hear vector buzzing sounds, but HV section not working.
Replaced ALL transistors,capacitors, and diodes(including ZDs and the diode rectifier inline of the HV to tube supply line-wire with suction cup) in the EHT(High Voltage) section.-Now all voltages check out fine, tried adjusting brightness,focus STILL NO PICTURE.
I am thinking there may be problem on the mother board. Can I plug this G05-805 into my Battlezone to test it?
Any body have any ideas?
Thanks for any help
Aaron
 
Ok now I'm more confused?! Voltages good, but still no picture!
Lets replay what I have done so far --got an Asteroids cocktail from a friend for repair. Plays blind with a totally dead G05-805 monitor.
Installed Bob Roberts cap/trans. kit- monitor now powers up (neck glow, can hear vector buzzing sounds, but HV section not working.
Replaced ALL transistors,capacitors, and diodes(including ZDs and the diode rectifier inline of the HV to tube supply line-wire with suction cup) in the EHT(High Voltage) section.-Now all voltages check out fine, tried adjusting brightness,focus STILL NO PICTURE.
I am thinking there may be problem on the mother board. Can I plug this G05-805 into my Battlezone to test it?
Any body have any ideas?
Thanks for any help
Aaron

A good way to test if you are getting HV to Tube is to put a piece of note book paper to the front of the tube. Seems to me that this is the only thing you have not checked. The paper will stick to the screen and if you messed with the brightness pots and HV pots and see no rastor then you are not getting HV to tube the paper trick will confirm that. GOD BLESS and Mery Christmas
 
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