Tascam 38 Problem

[RAH7788]

I have a Tascam 38 that will play with no problems but it wont record audio on any tracks at all. When trying to record on any track the erase head is working but no audio gets on the tape. in playback mode both the sync and repo heads are working on all tracks,

 

[sweetbeats]

So you can see signal when monitoring the input?

Record enable switches switched in?

Not trying to be insulting by asking the obvious. I've done some really air-headed things in the past and always appreciated it when it was pointed out.

What's the history of the deck?

 

[RAH7788]

Tascam 38

Yes the Record switches are pushed in and i see audio on the meters when selecting input or sync for the output options. The machine worked perfect when last used a year ago. I can playback old tapes and bet audio from both sync and repo heads but it wont record anything on any track now.

 

[sweetbeats]

The record-ready LED's are flashing when you push the switches in and then they go steady when you put the transport into record mode?

 

[pianodano]

I have 2 of them (38's) that are doing this too. 1 of the machines had less that 40 hours on it. Both recorded fine a couple years back. I suspect the relays but I haven't had time to get into them yet.

Danny

 

[sweetbeats]

Wow...Danny...you think so? Could they all do that at once like that?

RAH7788...let's follow dano's idea. He's a smart cookie.

Have you ever experienced removing and reinstalling any of the amp cards on your 38? It is not hard to do if you haven't done it before...that might be the first step, what we call "reseating" the amp cards. Beyond that it is cleaning the relay contacts. The relays are on the amp cards...two each, 16 total. I did this on my 58 and it worked wonders.

Do you have a full manual for your 38?

 

[pianodano]

Wow...Danny...you think so? Could they all do that at once like that?

RAH7788...let's follow dano's idea. He's a smart cookie.

Have you ever experienced removing and reinstalling any of the amp cards on your 38? It is not hard to do if you haven't done it before...that might be the first step, what we call "reseating" the amp cards. Beyond that it is cleaning the relay contacts. The relays are on the amp cards...two each, 16 total. I did this on my 58 and it worked wonders.

Do you have a full manual for your 38?

I don't know. But both of the machines were exposed to smoke. You gotta remember nearly everyone smoked way back then. I pulled the cards and cleaned the connectors with Deoxit. That didn't help at all. Meters show signal at usual places, but no record. Relays seem most likely culprit. Were you having problems with relays on your 48 ?

 

[sweetbeats]

No, no problem with the 48 relays...it was the 58. Do you remember that way-back-when over at the Tascam Analog forum? IIRC you were involved in helping me figure out what to do...resoldered the amp card connectors, cleaned the relays and the thing was a different machine...don't think it was ever smoked around...you can kind of tell. My problem was wierd-wierd-wierd inconsistent to non-existent levels moving from track to track particularly when monitoring off the sync head. It was distressful. I have a hunch it was mainly cleaning the relays that fixed things up but it was a different machine after that. Solid levels, crisp response when switching monitoring sources on the deck...you could really hear the relays *click*...used DeoxIT of course.

 

[RAH7788]

Led's

Yes the led's light and i have pulled out the cards and cleaned them wit deoxit but no change. I do not have a manual for it. Hard to believe that many relays quit at the same time. Wish i had a schematic for it. I have been wondering if there is a power suply source for the record relays that may have droped out or something. I do alot of Pro Audio repair work but this machine has me stumped...lol

 

[SteveM]

There are fuses. About 10 of them. I don't know if that could cause it but check them out.

 

[pianodano]

Yes the led's light and i have pulled out the cards and cleaned them wit deoxit but no change. I do not have a manual for it. Hard to believe that many relays quit at the same time. Wish i had a schematic for it. I have been wondering if there is a power suply source for the record relays that may have droped out or something. I do alot of Pro Audio repair work but this machine has me stumped...lol

I sure hope you'll let us know if you figure out what the problem is. This seems to be a widespread issue lately with 38's.

Danny

 

[RAH7788]

All of the fuses are good, Next week when i have time i will dig into the power supply and see what might be wrong, does anyone know where i can get a schematic for this thing?

 

[pianodano]

All of the fuses are good, Next week when i have time i will dig into the power supply and see what might be wrong, does anyone know where i can get a schematic for this thing?

The record/reproduce amplifier and power supply PCB is on page 103 in the manual. Do you have one ?

There are about 28 caps, 10 transistors,6 diodes, 65 carbon resistors, 7 variable resistors, 6 choke coils and 3 relays on each channel card plus a whole slew of misc other crap. I can't figure anyway to scan it. It's kind of big.

K103= record relay. K102= power mute relay. K101= sync relay.

 

[RAH7788]

That info does help a little bit, I will trace the circuts the old hard way without the schematic so knowing which realy does what, that hepls save me some time. I will post what i find from there so the info can get passed out to help others with this problem.
Thanks!

 

[foreal]

i have a tascam 38 wont record

same problem with my deck,, plays old test tone tapes o,k, ..and meters jump on record mode but they dont jump on play back , with dead air, also had the rotten pinch roller sticky shed delema and still am worried to replace the belt. should i take the machine to a t,v, repair man or do i fix it my self,,

 

[pianodano]

same problem with my deck,, plays old test tone tapes o,k, ..and meters jump on record mode but they dont jump on play back , with dead air, also had the rotten pinch roller sticky shed delema and still am worried to replace the belt. should i take the machine to a t,v, repair man or do i fix it my self,,

Maybe hold off a bit. As I mentioned, it seems to be a nearly universal problem with 38's now. Maybe someone can figure it out pretty quick.

 

[jpmorris]

That info does help a little bit, I will trace the circuts the old hard way without the schematic so knowing which realy does what, that hepls save me some time. I will post what i find from there so the info can get passed out to help others with this problem.
Thanks!

I can scan in the '32 card schematics if they're any help. The boards are slightly different from the '38 but the same basic design.