Please hel me for Willem Eprom Programmer PCB45

By: demonlg - 2008-07-08 03:18:36

Hi, i need to write any TMS2532jl45 with my willem but it's not supported on 4.5 PCB, i have create an adapter for this operation and now i read fine all 2532's, but i don't write on new blank eprom!

I have an older TMS2532 dissoldered from my Commodore PET computer, i have erased this with UV and than i have reprogrammed it with different bin perfectly with my willem+my adapter !!

Why i program the older and not the newest?

The new TMS 2532 need Vpp up tu 25 volt for programming, but i have tested pin 21 of older 2532 at the programming state and the value is 18,5 !!!! The older need different voltage?

Sorry for my english i'm italian!

Please help me!

My mail is bemanuele@libero.it

Emanuel

Re: Please hel me for Willem Eprom Programmer PCB4

By: DL - 2008-07-08 21:26:42

Hi Emanuel,
Emanuel wrote on 07/08/08 at 03:18:36:
The new TMS 2532 need Vpp up tu 25 volt for programming, but i have tested pin 21 of older 2532 at the programming state and the value is 18,5 !!!! The older need different voltage?
It may have just been chance that you had an EPROM that would program at VPP lower than 24V.  It wasn't programmed reliably...

You may be able to fix the low VPP problem by using a better coil.  One that saturates at > 300mA.  Test your fix by adding a 30mA load and making sure the programmer can maintain for 60 seconds without dropping below 24V.  The default tWP for 2732 (1.2mS) is too low, you should change it to the max (12mS - should be 50mS).

You probably also have problems with VCC drop.  Apply a 160mA load to make sure you can handle all TMS2532.

HTH,
Dennis

Re: Please hel me for Willem Eprom Programmer PCB4

By: demonlg - 2008-07-08 22:40:46

Hi, thanks for fast reply, i have a little experience in electronic repair and i d'n't have any schematics or any component list for this modify on my willem board, probably i have a drop problem.

I have connected my external powersupply with max 30 volt input but in a pin 21 i have the same value 18,5 volt !

This night i have blowned the 7805 on my willem board because i have overvolted it with 37 volt, now my willem don't work with external power supply but working perfect with USB connection from PC!

How i fix VPP ?

What coil must replace or add and where?

How to fix VCC drop?

How does the increase in load 160ma?

Please if is possible send me any schematics or component used and any position for soldering on my PCB, i need to repair my PET!

Re: Please hel me for Willem Eprom Programmer PCB4

By: DL - 2008-07-09 01:23:52

Hi,
Emanuel wrote on 07/08/08 at 22:40:46:
Hi, thanks for fast reply, i have a little experience in electronic repair and i d'n't have any schematics or any component list for this modify on my willem board, probably i have a drop problem.
I don't think Sivava provides schematics.   Check their website to see if you can find anything.   The inductor is the blue component between the step-up regulator and USB connector.   It looks like they're using an inexpensive molded variety that's probably saturating.
Quote:
I have connected my external powersupply with max 30 volt input but in a pin 21 i have the same value 18,5 volt !
Maximum input voltage should be 12VDC.   Increasing input voltage won't help the VPP problem because the step-up regulator is powered by the 7805.
Quote:
This night i have blowned the 7805 on my willem board because i have overvolted it with 37 volt, now my willem don't work with external power supply but working perfect with USB connection from PC!
7805 should take 35V.   With the rectifier diodes, you shouldn't have been much more than that.   It's possible that you popped the filter cap.
Quote:
How i fix VPP ?
Replace the inductor with one rated for at least 500mA+.  If that doesn't help, you need to replace the step-up regulator with a linear regulator; that's not a component swap.  I have a schematic for a mod that fixes the VPP and VCC problems on PCB3 variants.  It's copyrighted, but free for your personal, non-commercial use.
Quote:
What coil must replace or add and where?
Coil is between the USB connector and the DIP8 regulator.
Quote:
How to fix VCC drop?
The better solution (IMO) is to add a relay in parallel with the transistor switch.   Others have tried using a transistor with a higher current rating/lower saturation voltage and driving it harder.   You'll still have a non-linear voltage drop in VCC to the sockets.

The best solution is to put the voltage drop of the switch in a feedback loop so the drop can be compensated.   I built a prototype and it fixes the VCC and VPP drop.
Quote:
How does the increase in load 160ma?
Enter the Test H/W tab, set programmer as indicated.   With no device in the programming sockets, insert a 30 ohm 1W resistor between pins 32 and 16.
Quote:
Please if is possible send me any schematics or component used and any position for soldering on my PCB,
Most PCB3 variants use similar VPP circuits.   Try this.
Quote:
i need to repair my PET!
Which PET do you have?   I have a 4032.

HTH,
Dennis

Re: Please hel me for Willem Eprom Programmer PCB4

By: demonlg - 2008-07-09 16:40:21

I have buyed the PCB4.5 from sivava site, and your link is the PCB i have!

Yes, maximum load for 7805 is 35 volt, if i overload from 12   to 24 volt the VPP do not change!

I have replaced the blowned 7805 with a new and i have added a fin dissipation, now the PCB back to working fine with 12vdc 500ma external powersupply.

I have found the inductor on my pcb, in effect is only one blue and between USB connector and step regulator, this inductor have printend on the top 101k value, on the hole in a PCB is printed 100uH,   what is the inductor value that I need to buy and replace? 500k?

For the VCC drop i solve the problem next to the VPP problem.

I have tested my board in TEST/HW, i have setted dip switch and test the pin 1 in a zif socket, without device on, and the VPP on pin 1 is 23,5 volt, if i stay one minute in this mode the value go down lowely from 23,5 to 22.8 volt! Probably low for my TMS2532, it neded 25 volt VPP!

The 30 ohm resistor betwen pin 32 and 16, is only for test, or i need this resistor for programming 2532?

Wow, i'm a COMMODORE collector, i have 3 PET family, the older to repair 8032 with 8050 dual drive, one 8296-D with internal 8250lp drive, and one 8296 with external 8250lp drive.

The 8032 in reality is working fine, but the ROM are older and i have to remake a new 2532 because hard to find in 2008   , the older 2532 programmed fine is a 901465-23 BASIC 4 ROM and work fine in my 8032 without socket adapter, because the original ROM are 2332 prom and the 2532 Eprom have the same pinout!

Emanuel   

Re: Please hel me for Willem Eprom Programmer PCB4

By: DL - 2008-07-10 16:26:45

Hi Emanuel,
Emanuel wrote on 07/09/08 at 16:40:21:
Yes, maximum load for 7805 is 35 volt, if i overload from 12   to 24 volt the VPP do not change!
The step-up regulator is powered by the 7805, so increasing the input voltage only affects your ability to generate VCC voltages above 5V.  Anything more than 12V just causes unnecessary power dissipation.
Quote:
I have replaced the blowned 7805 with a new and i have added a fin dissipation, now the PCB back to working fine with 12vdc 500ma external powersupply.
What is the voltage rating of the filter cap?  37V may have damaged it.
Quote:
I have found the inductor on my pcb, in effect is only one blue and between USB connector and step regulator, this inductor have printend on the top 101k value, on the hole in a PCB is printed 100uH,   what is the inductor value that I need to buy and replace? 500k?
You might be able to use a higher value, but without analyzing the circuit, I'd use 100uH with a saturation current above 500mA.
Quote:
For the VCC drop i solve the problem next to the VPP problem.
Replacing the 7805 doesn't fix the VCC drop problem.
Quote:
... VPP on pin 1 is 23,5 volt, if i stay one minute in this mode the value go down lowely from 23,5 to 22.8 volt! Probably low for my TMS2532, it neded 25 volt VPP!

The 30 ohm resistor betwen pin 32 and 16, is only for test, or i need this resistor for programming 2532?
Anything below 24V is too low.  The resistor is only for testing.

HTH,
Dennis

Re: Please hel me for Willem Eprom Programmer PCB4

By: demonlg - 2008-07-11 00:05:16

Ok, now i use 12volt max power input for my pcb!

The voltage of the filter cap is 16v......yes may be damaged it! tomorrow i buy all new caps on the pcb!!!

Mmmmm, if i have on PCB the 101k inductor i think it is 100uh but i don't know the saturation current it is............When I go to buy the new must ask 100uh and current saturation greater than or equal to 500mA?

Yes, the 7805 don't solve VCC drop but VCC in my PCB is great for 2532 and 2732, i have burned correctly more 2732!

Ok, 24 or little higher is ok for my 2532 but below 24 is all wrong voltage!

Thanks, i will write you when i replaced all caps, and inductor, if i have the same problem with programming 2532 please How can I get your plan? I have to pay you?

Emanuel

Re: Please hel me for Willem Eprom Programmer PCB4

By: DL - 2008-07-11 01:04:36

Hi Emanuel,
Emanuel wrote on 07/11/08 at 00:05:16:
The voltage of the filter cap is 16v......yes may be damaged it! tomorrow i buy all new caps on the pcb!!!
You only need to replace the filter cap.  The bypass caps are probably rated at 50V or higher.  The storage cap on the step-up regulator wouldn't have been affected.
Quote:
Mmmmm, if i have on PCB the 101k inductor i think it is 100uh but i don't know the saturation current it is............When I go to buy the new must ask 100uh and current saturation greater than or equal to 500mA?
Whoever you buy the inductor from should have it's specs.  Select something with a saturation current above 500mA.
Quote:
Yes, the 7805 don't solve VCC drop but VCC in my PCB is great for 2532 and 2732, i have burned correctly more 2732!
You might be surprised by the magnitude of the voltage drop.  You can do an experiment with some of your 2732/2532.  Set your programmer for 2732, enter Test H/W tab, insert an EPROM, enable VCC and measure the voltage at pin24 of the EPROM.  I've seen voltage drops of up to 2V with Hitachi 2532.  If the voltage is higher than 4.5V and you've been setting tWP to 12mS, they might be programmed reliably.  I prefer to program at VCC=6V and tWP=12mS.
Quote:
How can I get your plan? I have to pay you?
It's free for your personal, non-commercial use.  I'll email it to you.

HTH,
Dennis