[Roadtrip] It's not a race (anymore), it's a RALLY

[Laschek]

ok, did some quick measuring during the lunch break:

the DC voltages on the IN side of the power block measure in at around 113 volts - shouldn't they be around 230?

I'm not sure if I understand you right, but that's AC going into the power block, not DC, so maybe you did just measure the wrong way 

anyway, i put the red and black multimeter leads on the two wires with the connectors (brown & white/green) and the DC measure i got was somewhat strange: around 0.80 volts. remember, this is with the tv NOT attached, but shouldn't it also be around 115 volts? any input on this? would you connect the PCB and the TV now and see what happens?

Ully, these are the wires which provide the TV with sound and picture, not power, so thankfully no 115 V there  . Video, Audio & GND. I guess they should come from pins 22 (Com->GND), 16 (audio), 20 (video). Just follow them back to the edge connector of the PCB, the actual wire colors don't seem to match the ones described in the schematic.

[Superully]

I'm not sure if I understand you right, but that's AC going into the power block, not DC, so maybe you did just measure the wrong way  

sure, stupid me. measures are right - i was just not intelligent enough to type AC so that's around 113 volts AC. could that be right?

Ully, these are the wires which provide the TV with sound and picture, not power, so thankfully no 115 V there  . Video, Audio & GND. I guess they should come from pins 22 (Com->GND), 16 (audio), 20 (video). Just follow them back to the edge connector of the PCB, the actual wire colors don't seem to match the ones described in the schematic.

i found the tv power connectors - they measure in at around 115 volts!

one question remains: is the position of those two connector wires important? or is it trial and error?

[Etienne MacGyver]

Its AC so that should not matter

[Superully]

Its AC so that should not matter

it DID matter, because as laschek said, this is NOT AC. made some progress, i'm uploading videos as we speak - stay tuned!

[Laschek]

it DID matter, because as laschek said, this is NOT AC. made some progress, i'm uploading videos as we speak - stay tuned!

You are confused  It IS AC.
We do speak from the voltage going into the power plug, do we? Coming from the wall plug, going through the fuse, etc. This is AC and you should measure 230 Volts of course.

[Superully]

ok, with the measures all looking normal to me, i connected both the pcb and the tv to their corresponding connectors. here's my setup



i then plugged in the game and pulled out the interlock switch. the power supply started humming, but nothing on the tv screen

ok, i exchanged the connectors on the back of the tv set and powered up the game here's the result

as you can see, the picture is shifted to the left, it is "jumping" and there is a line running through the picture, but it's a start!

i found the "hidden service menu knobs" on the back and managed to center the picture. i pushed down the credit coin-up microswitch here's the result

note that the dash on the left is much larger than the one on the right. PLUS you can hear this ball sound as if it were bouncing around. however, the controls were disconnected. so i took the entire control panel and attached it. when i restarted the game and credited it up, the bigger dash on the left was gone, but the bouncing sound was still there!

i tested the controls here's the result

as you can see, the controls are not responding perfectly and they are "jumping" a little bit, but they work! the problem is that the ball is still missing (am i supposed to serve it somehow?) and that the picture is of mediocre quality!

question: where's the ball?

[Superully]

We do speak from the voltage going into the power plug, do we? Coming from the wall plug, going through the fuse, etc. This is AC and you should measure 230 Volts of course.

yes, but the voltages before and after the power supply both measure in at around 115 volts. and the two connectors going to the UHF TV input are for video, audio and ground - and i have no idea whether those are AC, DC or WHATEVER-C, because the game seems to be working. not perfectly, but at least there's something on the screen which looks like PONG

[Laschek]

but at least there's something on the screen which looks like PONG

Looks more like RALLY to me 

[Laschek]

Soo, maybe it's a good idea to do some more measuring. You should check if the board gets a good +5V. I recommend measuring at the voltage regulator (that thing surrounded by the heatsink). This part should be the last part in the +5V circuit and give out, well, around +5V DC...
Alternatively you can pick a random IC from the board, find its pinout on the net and check on its respective +5V and GND pins.

[level42]

Ully, do they have some summer courses in electronics around your school ?

You really need to get the grips on the basics.....you still have 50 cabs to go.......

as you can see, the controls are not responding perfectly and they are "jumping" a little bit, but they work!

I have one advice REPLACE THE POTMETERS. They are 37 year olds. They are GONE. Buy NEW one's.
Don't go fiddling with contact spray, it won't work (in the long run), it's more likely to make things worse.

the problem is that the ball is still missing (am i supposed to serve it somehow?)

Read the instructions on the Control Panel (No "Insert coin" texts on screen in those days ) So, credit it and the ball will serve...(if it will work OK)

and that the picture is of mediocre quality

............it is a TV of 37 years old and you're complaining ? Man, you are very lucky that it is already as far as it is !!!

There maybe a focus control that may be able to improve it. New caps can also do wonders on B/W monitors...
If all that fails, rejuvenating the tube may be necessary....

[Laschek]

the problem is that the ball is still missing (am i supposed to serve it somehow?)

Read the instructions on the Control Panel (No "Insert coin" texts on screen in those days )

He did push the credit switch   but I don't think you necessarily have to serve the ball. Many early games start right when a coin is inserted, Tank comes to my mind FI.

EDIT: André, did I skip a part of your text or did you edit that part in about the ball will serve when credited?

In any case, never mind my post... 

[level42]

The instructions on the CP say that the ball will serve automatically after inserting a coin (else it would need a serve button).

Didn't read that he pushed the credit switch...there you go, my mistake !!! 

There's bound to be some problem(s) on the PCB....but I agree with Laschek, measure the +5V somewhere on the board.

[Superully]

He did push the credit switch  but I don't think you necessarily have to serve the ball. Many early games start right when a coin is inserted, Tank comes to my mind FI.

yes, i did credit the game. when you do that, the horizontal line from the first video disappears and the score resets to ZERO! but no ball ...

[Laschek]

There's bound to be some problem(s) on the PCB....but I agree with Laschek, measure the +5V somewhere on the board.

With some luck it may be a very simple solution. I had a Stunt Cycle PCB with a bad picture and you couldn't start the game. Turned out it was a bad cap (the big one) on the 5V circuitry, nothing more.

[Superully]

Ully, do they have some summer courses in electronics around your school ?
You really need to get the grips on the basics.....you still have 50 cabs to go.......

i know, andré, i know, but i'm trying hard. i've bought the randy fromm dvds, but brian forgot to include them in my last shipment . hopefully they will advance my elelctronic skills a little bit - THEY NEED TO!!!

btw, it's not 50 cabs to go, it's like only half of it!

I have one advice REPLACE THE POTMETERS. They are 37 year olds. They are GONE. Buy NEW one's.
Don't go fiddling with contact spray, it won't work (in the long run), it's more likely to make things worse.

alright, point taken. where's the best place to get them?

............it is a TV of 37 years old and you're complaining ? Man, you are very lucky that it is already as far as it is !!!
There maybe a focus control that may be able to improve it. New caps can also do wonders on B/W monitors...
If all that fails, rejuvenating the tube may be necessary....

don't get me wrong, i'm absolutely thrilled that the game is working as it is at the moment, i hadn't expected it to work like it does. i'll open up the tv at the weekend, have a look at the caps and order replacements.

i'm going to measure the voltages on the board first though!