Dead Ibanez PH10

[effectsbay]

Hello All

A friend of mine called and asked if I could help with his broken Ibanez PH10. I figured it would be something simple. I forgot rule #1.. nothing is ever simple.

The pedal is completely dead. No bypass signal and the LED does not light up. I opened it up and started seeing some junk/gunk around the C33 and D5. I figured it was blown there, but after further exploration, that looks like something might have leaked on it (a long time ago). Cleaning it, the components appear to be good. I'm also seeing a good 9v when I meter it.

Looking a the schematic http://8bitsindgenug.net/ibanez_ph10.png I am reading 9V and 4.5V where it's suppose to be, but the ribbon to the sister board (where the pots and LED, is not showing good voltage. Really low.. like 2V. I tested the LED, and it lights up with diode test. I still feel like it's something really simple.. just see it.

Any recommendations on where to look? When the pedal died, there was no 'trauma'. It was not dropped, etc. Just didn't fire up. Also, the power supply has been the same.

Thanks!
hank

[MrStab]

whereabouts are you reading 9V and 4.5V? only in the power filter/voltage divider area (D5, R60 etc.)? are any of the IC's receiving power?

i think the LED is a clue to at least one problem. check if you read V+ on the anode of the LED, and if not, go back to where it meets the rest of the supply rail (or where you do get a reading). Then check for issues between those points. If you do get V+ on the anode, then check for continuity between R69 on the main board and the LED cathode (so you know which side of the resistor is which), hook up a wire to ground via. the enclosure or something, and use the other end to touch the opposite (non-cathode) side of R69. see if the LED comes on. if it doesn't, check D3 then TR3's connection to ground (via. emitter).

[MrStab]

damn, forgot what you said about the ribbon. what if you connect a new wire to a healthy V+ spot on the main board and connect it in parallel alongside the current one to the daughterboard? worth a shot. maybe look for shorts or damaged traces on the daughterboard, too.

[effectsbay]

whereabouts are you reading 9V and 4.5V? only in the power filter/voltage divider area (D5, R60 etc.)? are any of the IC's receiving power?

i think the LED is a clue to at least one problem. check if you read V+ on the anode of the LED, and if not, go back to where it meets the rest of the supply rail (or where you do get a reading). Then check for issues between those points. If you do get V+ on the anode, then check for continuity between R69 on the main board and the LED cathode (so you know which side of the resistor is which), hook up a wire to ground via. the enclosure or something, and use the other end to touch the opposite (non-cathode) side of R69. see if the LED comes on. if it doesn't, check D3 then TR3's connection to ground (via. emitter).

Grabbing the meter, and touching the ground on the input jack to the anode of the LED, I get .10v. I get that value in a few places. I can also get that value before the ribbon to the daughter board.

hank

[MrStab]

whereabouts do you get 9V? D5 & C33? i can't really tell from photos of the PH-10 underside where V+ goes next (although it's probably a plane).

do your readings change all of a sudden if you move or bend the board slightly, or are they constant? if they keep changing, you should check for bad solder joints. especially ones holding wires in.

[duck_arse]

rule #1.. nothing is ever simple.

I figured it was blown there, but after further exploration, that looks like something might have leaked on it (a long time ago). Cleaning it, the components appear to be good.

..... When the pedal died, there was no 'trauma'. It was not dropped, etc. Just didn't fire up.

is there any chance the gunk might be a spilt cola-style drink? if so, you might be missing some copper traces. look closely at the case/baseplate in the areas under where the gunk was, is there any puddles/signs of liquids?

[effectsbay]

rule #1.. nothing is ever simple.

I figured it was blown there, but after further exploration, that looks like something might have leaked on it (a long time ago). Cleaning it, the components appear to be good.

..... When the pedal died, there was no 'trauma'. It was not dropped, etc. Just didn't fire up.

is there any chance the gunk might be a spilt cola-style drink? if so, you might be missing some copper traces. look closely at the case/baseplate in the areas under where the gunk was, is there any puddles/signs of liquids?

That's interesting could be. I put some contact cleaner and got most of it off. I do see the copper.. looks like it removed some of the 'green' on the board. But, I am getting 9V at the point of the gunk though.

Thanks!
hank

[effectsbay]

whereabouts do you get 9V? D5 & C33? i can't really tell from photos of the PH-10 underside where V+ goes next (although it's probably a plane).

do your readings change all of a sudden if you move or bend the board slightly, or are they constant? if they keep changing, you should check for bad solder joints. especially ones holding wires in.

Yes D5 and C33 I get 9V. After that, I see it goes to a resistor, which I'm unable to read the resistor number, but things get weird there potentially.

Thanks!
hank

[PRR]

> ribbon to the sister board (where the pots and LED, is not showing good voltage.

Most of that stuff isn't DC powered; not sure what you expect to see.

One pin of the LED should show full +9V. Does it?

Power pins of each IC should show full +9V. Do they?

> ground on the input jack to the anode of the LED, I get .10v

Good place to start looking for a bad joint or burnt trace.