Help Me Get My GTE 120B Phone Working?

[olePigeon]

Found some cracked solder joints on the chassis where the keypad plugs into.  Reflowed the solder

Still same old same old.

So I looked over carefully the little pamphlet that came with my phone, and decided to try different strappings.  So I set it to semi-postpay with the coin slot disconnected (as indicated), and ...

Crisp & clear dial tone and my keypad makes tones!  Still can't dial out, but this is the best progress I've made.

Man, what the heck.  I thought I had to have it set to prepay, but I guess that mode will only work with a fancy & expensive phone controller that I don't have (although I'd dearly like to get one if I knew it would work with my particular phone.)

[olePigeon]

And with a reset of my BlueTooth adapter I'm able to make outgoing calls.  YAY!

[olePigeon]

Oh darn.  I can make and receive calls, but no one can hear me.  Although I hear them fine.

[RDPipes]

Oh darn.  I can make and receive calls, but no one can hear me.  Although I hear them fine.

Sounds like you may have transmitter capsule that is bad.

[TelePlay]

Sounds like you may have transmitter capsule that is bad.

Yes, could be the carbon in the capsule has clumped or the contacts are dirty or not pressing enough against the element contact rings.

Did you clean off the element rings, the contract spring tips (with a non-abrasive material - IIRC a rubber erasure does the trick) and pull the spring contacts up a bit for better contact?

[Stan S]

If you hear yourself in the receiver when you speak there is nothing wrong with the mic capsule. If you are using an XLink make sure the outgoing audio is turned up. That is something orogrammable.

[olePigeon]

Thanks for all the help.

Sounds like you may have transmitter capsule that is bad.

I have not checked it.  The handset is (was) new, although it may have dropped onto the table a few times when it fell off the hook.

I have a conversion kit that lets me plug the handset into it.  I'll try it on that first and see if it's working with that.  Then I'll know for sure.

If you hear yourself in the receiver when you speak there is nothing wrong with the mic capsule. If you are using an XLink make sure the outgoing audio is turned up. That is something orogrammable.

I do not hear myself.  I have a Cell2Jack.  I never had to set anything for it before, but I'll look.  Only option I see is "MIC Volume."  That could be it.  I also noticed an option for "Offhook Power."  I'll try both of those.  https://www.cell2jack.com/setting.html

Incidentally, do you think the XLink is better than a Cell2Jack?  Looks nicer, anyway.

[olePigeon]

OK, I've verified my receiver is working fine.  Works as expected on my plastic conversion kit.

When hooked up to the chassis currently installed, I get a nice loud crisp dial tone, but zero voice.  The person on the other end hears what I would describe as "squiggles."

I then configured my other 120B chassis identically to the one currently installed.  First, the ringer doesn't ring.   Second, I can hear myself on the receiver just fine, but it ends up quiet and garbled on the other end.  Third, the dial tone is very quiet, but my voice / breathing coming back on the receiver is robust and loud.

Since neither of these chassis came with my phone (it came pre-configured with the conversion kit with a janky electronic bell) and I bought them 2nd hand for $20 as "used, unknown condition," I'm going to assume that both of my boards are just bad.  Probably came from a broken pile of pulled chassis and sold to ignorant people like me.

One of the transistors looks like its falling apart and I can see white cotton stuff sticking out of it.  I can't imagine it's working too well (if at all.)

I think I'll have to hang this one up (hah) until I can test it with a known good chassis.

[olePigeon]

Well. I have two chassis.  Maybe I can cobble together working parts to get one good chassis together.

I have a cheap component tester, so I can check the transistors, diodes, etc.

[RDPipes]

One of the transistors looks like its falling apart and I can see white cotton stuff sticking out of it.  I can't imagine it's working too well (if at all.)

Can you photo this for us, I don't believe I've seen anything like what you describe.
A capacitor leaking yeah, but a transistor opening up with cotton like stuff no.
If nothing else I'd certainly replace what ever component it is.

[olePigeon]

Can you photo this for us, I don't believe I've seen anything like what you describe.
A capacitor leaking yeah, but a transistor opening up with cotton like stuff no.
If nothing else I'd certainly replace what ever component it is.

Sure, when I get home.  It's an old style transistor.  Not like the plastic packages we have today.  Looks kinda like a capacitor.

[RDPipes]

Sure, when I get home.  It's an old style transistor.  Not like the plastic packages we have today.  Looks kinda like a capacitor.

Yeah, a little short can, right? Never seen one open up like a bad cap.

[olePigeon]

On closer inspection it's not cotton coming out of it, but it looks to be the coating they put on it for ruggedization.  However, the top of the can is still clearly coming off.

[olePigeon]

Hmm.  Seeing that blob of less-oxidized solder near the transistor and the melting of the coating all around it is making me think there was a repair attempt before I ever got it.  Either that, or that transistor got super hot.

[olePigeon]

The uploaded PDFs that I can find for the schematics are impossible to read.  Wasn't scanned at a high enough resolution.  There's allegedly a parts list, but I can't read it.