[Restoration] The Joust Begins ...

[Superully]

You should measure 3V (maybe something less). If there's no voltage you have a bad connection from the battery holder. If there's less than 2V it is possible that one of the 2 diodes (the one arrowed and the one close to it) is bad (one of those should essentially stop the board being juiced from the battery: if it's bad the battery juice all the board, even when switched off, and the battery goes low fast).

i've went to my mother's place during one of the school breaks quickly and had about 5 minutes to do some measurings - hope i didn't get any wrong results because of the hurry! well, the voltage measures for the battery came up with 0.91 volts

when you were talking about the 2 diodes which may be malefunctioning, i remember that someone else on the klov forum was already talking about this. i had posted a picture of the battery area because i had the feeling that there was still some corrosion / acid damage going on. have a look at the following picture



i did NOT remove any components from the board to get the following results:

- the resistor R26 which shows signs of acid damage is testing fine, however the one next to it (labeled R28 and circled in red) should give me a reading of 4700 Ohm with a tolerance of 10 % (yellow - purple - red - silver). i've measured that resistor multiple times now and it only gives me 3200 Ohm.
-then, i've measured the diodes D1 and D2 whose legs look somewhat corroded. this could be the reason why getting a reading of the measures is not always easy, sometimes it works, sometimes i have to move the multimeters tips around a little bit to make it work. D2 is fine, blocking the current in one direction and giving a reading of around 600 in the other. well, at least the video tutorials i've watched on youtube told me that those are good readings . D1 (circled in blue) however is also blocking the current in one direction, but gives me a negative reading of around -500 in the other direction. isn't the output always supposed to be positive?

you can find my old thread about this on KLOV here!

i guess it would be a good idea to replace those diodes and resistors ...

[SeTTleR]

Hi Ully,
I don't know anything about your PCB, but I have some remarks: The value that you measured from the resistor can be good, because you don't know circuit surrounding it. So measuring with all parts soldered in can give you wrong results, because you don't know what exactly you measure. The value that you are measuring there might be the one of other resistors or you measure a parallel circuit or something else.
About the negative voltage: try swapping the red and black sticks of your multimeter and the measuring points (not plugging them in and out, just use the other measuring point).
Anyway, I hope you get that fixed soon! 

[Superully]

I don't know anything about your PCB, but I have some remarks: The value that you measured from the resistor can be good, because you don't know circuit surrounding it. So measuring with all parts soldered in can give you wrong results, because you don't know what exactly you measure. The value that you are measuring there might be the one of other resistors or you measure a parallel circuit or something else.

that's why i wrote "i did NOT remove any components from the board to get the following results". as far as i know, those measures should be done with at least one leg removed ...

About the negative voltage: try swapping the red and black sticks of your multimeter and the measuring points (not plugging them in and out, just use the other measuring point).

thx, but i think i tried both variations. i will go over it again tomorrow though, just to make sure!

Anyway, I hope you get that fixed soon! 

me too, after all that painting and repairing, I WANT TO ENJOY THAT GAME!!!

[baritonomarchetto]

If the diode stops completely current flow in one direction it should be ok, no matter what is measured on the other side (even if a negative value is nonsense: it's a resistance and it's always positive).

The voltage value is low and can be the cause of yor board "failure". Try removing the battery from the board and measure the voltage directly

[Superully]

The voltage value is low and can be the cause of yor board "failure". Try removing the battery from the board and measure the voltage directly

on the same two spots for the multimeter leads - diode leg and "ground hole"?

[baritonomarchetto]

No Ully: remove the battery from the battery holder. If the voltage of the battery ALONE is 0.9V the holder is ok and the battery went low (maybe because of some bad diode). If the voltage of the battery itself is higher the holder needs reflowing

[Superully]

thx a lot, i'll do some more testings tomorrow in the afternoon! it's time to watch soccer now

[baritonomarchetto]

Have fun 

[level42]

Also DO NOT MEASURE ON THE LEGS but on the solderings on the solder side. The legs obviously have some external corrosion, but this doesn't mean that the legs  themselves are bad or the part....

[Superully]

i've just come home with the sole battery voltage results:

0.90 volts !!!

the last time andré measured it after his battery installation, the result was something like 3.25 volts, so something must have sucked up that voltage somewhere ...

questions:
- can i put in a new battery for a short one-time test run without the voltage being drained out of it immediately?
- or is something blocking / draining the correct voltage, no matter whether i have a new battery installed or the old one?
- how can i test which component(s) is (are) malefunctioning? logic probe? multimeter?

[level42]

Was it maybe shorted by something conducive ?

You can put in a new battery for a short time to test.

But....is the board still not working at all or is it just that it won't keep the scores ? Sorry I lost track....

[Superully]

But....is the board still not working at all or is it just that it won't keep the scores ? Sorry I lost track....

no problem . it passes the rom test now, but it won't start the game because it remains stuck in bookkeeping. the switches which should allow to exit the bookkeeping screen aren't responding which could be caused by a low battery or an error in the interlock circuit (which could be the cause for a low battery). i will put in a new one later for testing purposes and report back with my results!

[Superully]

bought a new battery today and measured it for correct voltages before putting it in - just to make sure i didn't buy a dead one!



turned on the game, bookkeeping screen comes on. however: this is supposed to happen once a new battery is installed to reset / clear / restore certain statistics



after that, the game has to be turned off and with the bookkeepings cleared, the game should come up in attract mode ...



YES!!!

as you can see, the screen orientation isn't set up correctly yet, but that's an easy fix



the game credits up and plays nicely! unfortunately, a new problem came up: there is no speech

damn, will this ever end?

[level42]

No it will never end, it's a part of this hobby....electronics of 30 years ago....would you step in a plane controlled by 30 years electronics ?

Anyway, we now need to know why the battery drained so quickly....Bring the board next week ully, I will show you how to check it.

[Superully]

No it will never end, it's a part of this hobby

it will end if you put a computer inside your cabs ...

Anyway, we now need to know why the battery drained so quickly....Bring the board next week ully, I will show you how to check it.

great, thx! i've already learned some nice stuff from you, but i'd love to expand my knowledge! do we need both boards or just the one with the battery?

btw, how difficult is it to check / repair / rebuild the original power supply? i'm still running the game on a switcher which is powered through the monitor. wouldn't it be better to use the original setup?