Oheyo. Been 3 years since my last post.
Picked up another car with a 2 post radio. Came with a Craig T701. It would light up, but all it would do is make occasional popping and crackle sounds on its own. Typical. Some time passed and I found a really nice Audiovox AVX-900. Hooked it up to power aaaaaand all it does is turn the cassette motor on with no tape in the slot. No lights, no display. That'll be a different post though.
I know neither of these radios are of great quality, but I would like to try and fix them before finding another pioneer super tuner.
With the Craig, my guess is either the Hitachi amp is bad, or its got bad caps in the amp section. Without a schematic, its going to be a crap shoot for diagnostics. Hopefully someone, or Perry, can point me in the right direction.
I know the right thing to do is to pull each cap and check them, but should I just go ahead and order the 8 caps in this area? I am assuming theyre all for the amp since they are right next to the unit.
If the caps are bad, is it possible to check the hitachi amp pack?
Picked up another car with a 2 post radio. Came with a Craig T701. It would light up, but all it would do is make occasional popping and crackle sounds on its own. Typical. Some time passed and I found a really nice Audiovox AVX-900. Hooked it up to power aaaaaand all it does is turn the cassette motor on with no tape in the slot. No lights, no display. That'll be a different post though.
I know neither of these radios are of great quality, but I would like to try and fix them before finding another pioneer super tuner.
With the Craig, my guess is either the Hitachi amp is bad, or its got bad caps in the amp section. Without a schematic, its going to be a crap shoot for diagnostics. Hopefully someone, or Perry, can point me in the right direction.
I know the right thing to do is to pull each cap and check them, but should I just go ahead and order the 8 caps in this area? I am assuming theyre all for the amp since they are right next to the unit.
If the caps are bad, is it possible to check the hitachi amp pack?
HA1377. I didn't think I'd ever see/hear that number again. Copy and paste the following list and fill in the blanks. If there is no blank space after the colon, add one between the colon and the numbers you enter. It makes it much easier to read.
DC voltage on all pins?
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
DC voltage on all pins?
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
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Glad to bring back some memories 🤣
VCC: 13.46v
Pin 1: 6.73
Pin 2: 13.15
Pin 3: 13.46
Pin 4: 0.00
Pin 5: 13.16
Pin 6: 6.72
Pin 7: 0.50
Pin 8: 0.00
Pin 9: 0.00
Pin 10: 5.14
Pin 11: 0.00
Pin 12: 0.50
When connecting it to power with the volume down all the way it had a large blue arc, but it didnt blow the fuse in my psu, nor was anything smoking. amp was a tiny bit warm after checking voltages.
Also, having never heard the speakers work aside from them popping and snapping in unison, I will give them a quick check tomorrow. I doubt they are both blown, but I can't rule it out.
VCC: 13.46v
Pin 1: 6.73
Pin 2: 13.15
Pin 3: 13.46
Pin 4: 0.00
Pin 5: 13.16
Pin 6: 6.72
Pin 7: 0.50
Pin 8: 0.00
Pin 9: 0.00
Pin 10: 5.14
Pin 11: 0.00
Pin 12: 0.50
When connecting it to power with the volume down all the way it had a large blue arc, but it didnt blow the fuse in my psu, nor was anything smoking. amp was a tiny bit warm after checking voltages.
Also, having never heard the speakers work aside from them popping and snapping in unison, I will give them a quick check tomorrow. I doubt they are both blown, but I can't rule it out.
Sadly, I knew nothing when I was working on head units that used this IC and was mainly just a parts changer.
Looking at the datasheet, pin 10 should have supply voltage. Does this IC appear to be original (looking at the solder connections)?
Do you have a scope?
With no power applied, which pin reads 0 ohms to the B+ supply voltage input?
Looking at the datasheet, pin 10 should have supply voltage. Does this IC appear to be original (looking at the solder connections)?
Do you have a scope?
With no power applied, which pin reads 0 ohms to the B+ supply voltage input?
The first time I measured it, none were at 0, or close. Closest was like 6 ohm. Went back and measured again, and all the pins changed the resistance by a good amount. Not sure if that was from user error or not.
Pin 3 is at ~1.5 ohm, only one closest to 0 ohm.
The solder joints match the rest, so I'm guessing it's an original.
I do have a scope. Older digital Tektronix. Need me to check input pins for signal?
Edit: I'm measuring on the bottom of the board, left to right, text facing me. I think that's correct as pin 9 is ground
Pin 3 is at ~1.5 ohm, only one closest to 0 ohm.
The solder joints match the rest, so I'm guessing it's an original.
I do have a scope. Older digital Tektronix. Need me to check input pins for signal?
Edit: I'm measuring on the bottom of the board, left to right, text facing me. I think that's correct as pin 9 is ground
Pin 10 should be connected to B+ (either ignition or constant). The power switch will need to be on.
Yes, you will eventually need to check for signal but you must get power to the IC, first.
Yes, you will eventually need to check for signal but you must get power to the IC, first.
The power switch was on though.
I don't think this radio has constant power. Just key on.
Is it possible I've got the pin order backwards?
Looking at the front of the IC, the pins are numbered left to right.
With pin 3 reading the closest to B+, I don't know what you have.
With pin 3 reading the closest to B+, I don't know what you have.
Work the power switch on/off repeatedly to see if the resistance from pin 10 to the B+ wire/terminal gets closer to 0 ohms.
will do. I'll get to it this afternoon when im home from work. ive also got some deoxit that'll spray in there as well.
Do you now get full 12v supply voltage on pin 10?
Does the IC produce audio?
If not, repost the DC voltage on the IC with the correct pin numbering.
Does the IC produce audio?
If not, repost the DC voltage on the IC with the correct pin numbering.
Welp the ooooooole Craig lives to play another song in my 1981 tercel sr5. I think the dirty power switch and flaky harness was part of it, but I found out it was also stuck in AM, and it has AM(?) and FM muting. Need to shift the right knob over but it looks good!
I will probably poke around in the audiovox and if I don't see anything obvious, I'll be back.
I will probably poke around in the audiovox and if I don't see anything obvious, I'll be back.
