SST39vf080 Again !!!

[ju200270]

Hello everyone, I homemade my willem PCB3bx and it´s works perfect. I did every pìn H/W test and differents VCC and VPP works fine. I can read perfectly the old Eeproms 27c512,64,..etc with no current drop.
Well my problem comes when I made my own Tsop40 adapter to read a sst39vf080, I can not get the chip ID. I follow Ezo steps at the only read forum of willem. These are:

By: EZo - 2008-09-19 11:29:42

- Chip should be desoldered from your equipments, contactpads cannot be used.
- Chip pin 10 is NC, no need connect to ZIF32/1 (Vpp, BU7/37)
- Chip pin 11 is NC
- Chip pin 12 is NC, don't apply resistor R1 2k2 (WP# not in use).
- Place 2 diods from ZIF32/32 (Vcc=5V) in line to chip pins 30 and 31, to have ~3.6V
- For external adapter ZIF32/22 has WE function and comes connected to chip pin 9
- For external adapter ZIF32/31 has A18 function and comes connected to chip pin 13
- A19 get from connector J4 , second pin from bottom side and to be connected to chip pin 37
- Chip pins 38 and 29 are NC (highest adress not required)
- Chip pin 22 (CE) connect to GND (ZIF32/16)
- All other chip pins are connected to related ZIF32 pins according name in your picture

I checked every pin from the chip trought plugged adapter to the programmer and everyone ends where it has to. The only weird thing is that I need 7 diodes to between ZIF32/32 and tsop pins 30,31 to get 3,4v aprox. When I call for chip ID VCC & VPP leds blinks twice and no need of VPP. I´ve tried 98a soft and runnig 97ja actually selecting Am29f080.After chip ID I get Mfr 0x02[---], Device 0x10 "in blank" and this is a picture after a read of the buffer.

Thanks for the forum.

[Ezo]

I need 7 diodes

2 diodes use to reduce voltage ~1.3V

I´ve tried 98a soft and runnig 97ja actually selecting Am29f080.After chip ID I get Mfr 0x02[---], Device 0x10 "in blank" and this is a picture after a read of the buffer.

Apply SW 0.97ja only. Device ID is important for further actions. Chip return in your case read result from first adress. Means some adress /data pin is wrong (no contact, short, break). Clean pins from flux.

[ju200270]

Hi Ezo:
Thank you for your reply and sorry to answer you back so late. Well I homemade your Ezoflash 4v4, tsop40A3. I did the test on the programmer and no problem at all, I can test every pin on the test hardware and getting 4,9v on them.
When I´m using a 18v power supply both regulator(12v,5v) get hot, if I´m using a 12v one everything gets normal temperature.
Only one weird thing, to get hardware present I need to check the Vcc box on test harware, after this is present but if I call the chip ID the red led blink twice and no hardware present.
I placed the 39vf080 on the adapter,using 97ja soft and no ID again, all 0xFF, red led blink twice again powering the chip for short time and nothing back.
It´s a Compaq presario bios chip with boot block, I am using the programmer because I couldn´t use the recovery mode. I am starting to think that the flash is probaly corrupted.

Any idea??? thanks in advance.

[Ezo]

When I´m using a 18v power supply both regulator(12v,5v) get hot, if I´m using a 12v one everything gets normal temperature.

Thats not normal. Come regulators hot in standby mode ? Measure inputs voltage, power supply can give more than marked.

Only one weird thing, to get hardware present I need to check the Vcc box on test harware, after this is present but if I call the chip ID the red led blink twice and no hardware present.

Hardware check should work without Vcc box marked in test mode. Test hardware can fail, if +5V fail (shorts, high current). This can be regulator temperature problem.

[ju200270]

Good news.....it´s programmed already.

I used ezo>will adapter,tsop40a3 and willem PCB3bx. Software 0.97ja selecting Am29f080, just one problem...Bios.bak file is 1.049bytes and is not fitting inside of selected chip(1.024bytes). I attach a picture comparing both, original file(bios.bak) and lectura2.bin(readed affter burn).

I would like to know if I could fit the original file selecting different chip on the list.
Thanks a lot for your help Ezo.

[Ezo]

Seems bios.bak is not real chip file, it is source for PC own BIOS reprogramming with programs AWDFlash, AMIFlash or other.
Compare files and try find extra bytes , remove from source to have chip size.

[ju200270]

Hi Ezo:
You were right again, platform.bin is added at the end of the bios file making it longer. I edited it and solder it back two times. I don´t know why everytime I desolder it from the adapter to the motherboard some bits gets corrupted. I checked it the programing but after I placed back the file changes. I´m using a standard solder and some flux to help on the cleannig but still doing the same.I don´t know if the temperature is making this effect but I don´t take more than 4 sec to desolder all the pins at once. Do you have any clue??

Thank you again.