Tascam 38 Question and Scenario

[Darkshark]

I have 3 Tascam 38s.... today I hooked each one of them up and ran mic input through the inputs and out to a mixer..... not going to tape and recording. Each unit has issues like on Deck (1) VU meter ch2 didn't register or twitch. Deck (2) VU ch7 and ch8 didn't work.

And on Deck (3) input on channel 2 showed up on ch7 VU........ I got these decks to try and have one good one. My question, is it difficult to change out channels to try and piece together a good deck. Any suggestions would be great.

I may be banging my head against the wall....but I want to get one good deck to work with.

How would you approach this problem?

Kind Regards

DS

 

[evm1024]

Hi When you say you hooked the mic to the inputs do you mean you ran the mic straight into the deck?

Assuming this to be the case:

Mic outputs are 10 mV or so. Line in on a tascam 38 for 0 VU is 316 mV. Plus your mic may need phantom power....

Get one of the free oscillator programs for a PC and set it up to generate a 0.316 V signal at 1000 Hz. You may need a meter to verify the output. Test this by running the signal to your mixer if you like. It should read 0 VU.

Un hook from the mixer and connect it to line in one channel at a time. The source should be set to input.

THis will let you know which channels inputs are working.

REgards, Ethan

 

[Darkshark]

I ran an SM58 into a preamp then to the deck..... I will look for the pieces to try your approach... sounds like a great start. Thank You !

 

[LUNE]

IF some of the problems on the 38s are on the channel cards you will be able to switch them out for other working channel cards on different machines. (this makes calibration of the machine even more important.)
however, I wouldn't make the assumption that the channel cards are necessarily bad - its possible also to have some solder joints not passing signal on the motherboard. I don't really know how common this is but there were a few like this on one of my machines, some on the input, some from the Repro. you can check the thread if you want to see how I fixed mine (none of these required switching out cards.) click the link on the last post for another thread that shows pictures of the machine disassembled. this might help you when you're taking the machine apart. mine was a 34, but they are fairly similar. https://homerecording.com/bbs/showthread.php?t=294413

basically, at first, I'd make a list of all the problems and decide which machine you want to tackle (you could look at the heads to help make this decision as well) then for the input problems, test for continuity with a multimeter from the inputs and see how far you get - in my case all my shorts were on the motherboard and most of them cleared up when I cleaned this with 99% isopropyl and deoxit. I used a toothbrush, it was pretty dirty from accumulated dust. to clean it up good, you've got to unhook a bunch of multipin connectors and take out the whole bottom section/assembly. I think its a good idea to clean the motherboard up, but if you wanted to try something to get it working before pulling this all apart, you could try following the bad input to the mother board - disconnect the multipin connector - spray a little deoxit on this area (on the male multipin connected to the motherboard) and see if that helps. for some reason mine seemed to have problems with continuity there on the motherboard where signals were carried across from one side to the other where they meet the channel cards.
take a look at your machines and if something doesn't make sense in how i'm explaining this ask for clarification - also, if you need help in getting the front off, look up threads about changing the belt on these machines - the 32, 34 & 38 are all pretty similar in many ways.
good luck!