Any repair logs for Stunt Cycle? video problem

[bit_slicer]

i am not getting anything anywhere! maybe .01v but that's it!

i'm surprised that i can even play the game without having any voltage??? the caps aren't marked on pcb so i was guessing on the C8 but i had nothing there and also nada on top of heat sink and LM309. took off edge connector and just thought i would test 16vac and 25vac and i got nothing! i don't think i'm getting AC from transformer....can you tell me what's the inputs and outputs on that?

how am i playin the game?

You might not be reading them correctly. You said you were ok with using the DMM - do you have it on the correct setting? Measuring AC voltage, you should have it on the VAC setting or the squiggly sine wave symbol. The probes should be plugged into Ground (black) and Volts (red), and not Amps. In VAC mode try measuring a wall outlet (be careful). Make sure you get a good 120VAC. On the DC setting try measuring a battery. I know it sounds silly, but the second rule of hardware troubleshooting is to start with something you know is correct.

 

[FlashbaxArcade]

You might not be reading them correctly. You said you were ok with using the DMM - do you have it on the correct setting? Measuring AC voltage, you should have it on the VAC setting or the squiggly sine wave symbol. The probes should be plugged into Ground (black) and Volts (red), and not Amps. In VAC mode try measuring a wall outlet (be careful). Make sure you get a good 120VAC. On the DC setting try measuring a battery. I know it sounds silly, but the second rule of hardware troubleshooting is to start with something you know is correct.

yes, i know the diff in a DMM! i did not read the voltage correct when checking the harness voltages though! i used the cage as ground instead of pin on harness itself.

i get 9.3vac on pins 3 and 4 which is prob the reason why i can play game but not all correct! also, there is still nothing on 25vac pins in harness!

problems with transformer then? if i knew pinout of transformer i could probably diagnose it but don't wanna take a chance and blow somethin with wrong leads on wrong ones!

 

[FlashbaxArcade]

ok...getting somewhere! i had a bad connection(female plug) on the transformer for the 25vac but reads 14.1vac. got 120vac at fuse. i don't see in manual schem where to read 120vac physically goin to pins on xformer but i do get it reading from reading pins 4 and 6, (they had piggyback-dual wires) so i figured this was power. so it looks like i get 120v into xformer.

that being said, now i get the following readings on xformer:

pins 7 and 9 9.3vac
pins 10 and 12 14.1vac

do i have a bad transformer?

 

[bit_slicer]

ok...getting somewhere! i had a bad connection(female plug) on the transformer for the 25vac but reads 14.1vac. got 120vac at fuse. i don't see in manual schem where to read 120vac physically goin to pins on xformer but i do get it reading from reading pins 4 and 6, (they had piggyback-dual wires) so i figured this was power. so it looks like i get 120v into xformer.

that being said, now i get the following readings on xformer:

pins 7 and 9 9.3vac
pins 10 and 12 14.1vac

do i have a bad transformer?

That still sounds ok for the LM309 to get you down to +5V. The -5V might be a different story. The +8V and +18V might be affected too, but I only see the +18V being used with the controls. The video signal is sourced by +5V logic, so I'd say you can rule out the transformer for now. Take another look at sheet 2 where the +5V and -5V are generated and try to measure those. Use a GND point on the board. Just don't cross the streams.

 

[FlashbaxArcade]

That still sounds ok for the LM309 to get you down to +5V. The -5V might be a different story. The +8V and +18V might be affected too, but I only see the +18V being used with the controls. The video signal is sourced by +5V logic, so I'd say you can rule out the transformer for now. Take another look at sheet 2 where the +5V and -5V are generated and try to measure those. Use a GND point on the board. Just don't cross the streams.

yeah games sounds are fine as wells as controls! so you think i don't think i have a xformer problem then?

i will look into the section on sheet 2 as you suggested!

 

[Oryk Zinyo]

Your transformer sounds good. You can probably change the input lines to different lugs to bring your voltages closer to spec if it becomes a problem.

 

[FlashbaxArcade]

That still sounds ok for the LM309 to get you down to +5V. The -5V might be a different story. The +8V and +18V might be affected too, but I only see the +18V being used with the controls. The video signal is sourced by +5V logic, so I'd say you can rule out the transformer for now. Take another look at sheet 2 where the +5V and -5V are generated and try to measure those. Use a GND point on the board. Just don't cross the streams.

update: i was just measuring ground in wrong places when i measured 1st! TTL trace(busses i guess) were reading +5 and did read -5 on outside pins of Q2. that should be where i read -5 correct?

 

[bit_slicer]

update: i was just measuring ground in wrong places when i measured 1st! TTL trace(busses i guess) were reading +5 and did read -5 on outside pins of Q2. that should be where i read -5 correct?

Between Q2 and C8. Sounds like your voltages are fine. If I had to guess, I'd say you have a problem with the logic somewhere on the board.

 

[FlashbaxArcade]

Between Q2 and C8. Sounds like your voltages are fine. If I had to guess, I'd say you have a problem with the logic somewhere on the board.

that's what i didn't wanna hear! lol i believe i've measured all correctly now so off to find someone to repair!

thanks for the advice and help