Resetting code on Pioneer DEX-77

[moparman7]

yes i tried that and it does nothing , that method only works if you have the code that works and you want to change the code to a different one, as per dex-77 service manual.

[newmember]

Bringing this back from the dead with hopes someone figured this out by now. I have SL 578 and the previous owner couldn't remember the code. Would like to make sure the unit still works like he said it did.

[sm7xvd]

Quote:

Originally Posted by newmember Bringing this back from the dead with hopes someone figured this out by now. I have SL 578 and the previous owner couldn't remember the code. Would like to make sure the unit still works like he said it did.

There's still no resolve to this. I've managed to get a dump of the EEPROM where the code is stored, but no success in translating it to a usable code.

S1230000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF0000000000000000F4
S9030000FC

In plain text it would suggest the code 4903, but it's to no avail.

If anyone has a unit with a known code, i'd be happy to read the memory of that unit too so that we may find out how the code is encoded into memory.
I'm also going to try and replace it with a blank chip. With a little luck they weren't programmed at all at the factory. The 93c06 is a compatible replacement circuit.

[sm7xvd]

Development was under way, and then.. Catastrophe struck.
I was so close.
I was experimenting with my storage oscilloscope to see if i could capture the data stream from the eeprom which holds the code. Things were going great, my scope just didn't have quite high sample rate enough to see the information relibly. So i sent the dex-77 off to a friend who has a much better scope, but when he wires it up, the blue smoke comes out. A capacitor and a transistor are fried, but after replacement the unit is still dead. Also just after i sent it off i found out that the PDH001 eeprom is just a rebranded X24C44, so it probably would have worked had i replaced it.
Now we'll never know.

Has anyone else figured out a way to unlock a unit where you've forgotten the code? Does anyone have a locked unit which they cannot use and might give me a try on it?

[glhs0075]

sm7xvd,

It sounds like you're further ahead then me, from what I've been able to figure out:
I recently contacted Pioneer about this, the response I got was that there was no reset code or password, and the part to repair it is no longer available.

I take this to mean that the above mentioned steps to change the pass code only work on an already unlocked unit (this is how I managed to change my code on my once working DEX, random button pushing with a non-funtioning display).

"Repair" requires replacement of a chip, but I'm not certain which one.

If you were closer, I'd send you my locked-out DEX to play with. As it stands, my plan is to continue with the 0001,0002, etc... sequence. It's too cold to go out to the car to input codes all the time now, but in the near future I hope to pull it and set it up on a bench inside my office.

[GhostDaytona]

I just bought a P47DH the other 1.5 din pioneer off of eBay, an I hope I don't have the same problem.

[sm7xvd]

glhs0075,

As i wrote the X24C44 is probably the correct replacement part, and it is available on ebay. You could try and get one and put in your unit. Assuming that the eeproms were not programmed in manufacturing, it should be as if you just took it out of the box. It's the PDH001 chip located in the back left of the unit which should be replaced. It is mounted in a socket, so it's quite easy.
This will not solve the more interesting part of the mystery, ie how the code is encoded in the memory, but might get your unit running :).

[glhs0075]

It will take me some time to get around to this, but I'll give it a try. Thanks for the help sm7xvd!

Edit: I'm not much of a 'technophile', do I want the DIP style chip?

[sm7xvd]

Yup, that's the one.