Discussion in 'Hardware troubles and Repair support.' started by jumperger, May 5, 2019.
DM7020HD, that is exactly the same as for DM8000HD
Hmm, in that case there is some fault with this dm7020 psu information,
Or it has to do with a later HD version.
I use the DM7020 HD psu
Hmm, okay as long you have the psu which pin 1 is the 14vDc, then it's fine to use for the dm8000hd.
See this picture for more info about the voltages of the dm8000hd psu.
Further, sorry for the confusion about the dm7020, it seems to be that the schematic I have is from the dm7020S receiver.
Thus, indeed, as Ts had already mentioned, the dm7020HD psu should also be usable for the dm8000HD.
Nevertheless, although the psu from the dm7020HD may give the Stop issue, but the dm8000hd psu not, I'll stay with the possible solution at my earlier post, the nand flash chip replacement.
Thank you for the picture, could tou give me some details on how to understand the table? Or perhaps these exist allready in the forum?
I also have to inform you that I changed a quartz on the board as I was told it is an often faulty part, was a 54000 Quartz.
I'm asking now if i put it in the wrong way? Is there something like + and - on the quartz?
Quartz question, it has no +\- thus it doesn't matter how this two pins crystal has been placed.
Psu table question, first table is the pin number, second the voltages, the rest are ohm measurements, measured between a ground spot and the measurement spot, from different power supply's.
when you, for example, measure the ohm value from pin 1 the 8.53K, and you measure a value close to this value, then you may assume that this voltage circuit may healthy.
Ohm measurements must be done while the psu is disconnected, and not may be powered.
Also, the high voltage caps on the hot zone must be unloaded before measuring or working on the power supply.
Ohm measurements, PSU disconnected from:
- main (240V) ?
- motherboard ?
- mains and motherboard ?
Thank you so much for your help !
Psu ohm measurements... Totally disconnected, thus no power cord and no connection to the motherboard and when connected disconnected hdd power supply.
Thanks , I'll do the tests tomorrow
Here's the sticker from my DM8000 PSU:
My measurements are different from yours (kOhm):
Pin. - kOhm - (yours)
1 - 8.57 - (11.91)
3 - 8.8 - (9.14)
4 - 9.68 kOhm - (4.43 M Ohm)
5 - 17,50 - (22.56)
6 - 17.50 - (22.56)
8 - 9.05 - (9.14)
10 - 3.05 - (31.07)
12 - 8.24 - (8.29)
13 - 8.24 - (8.29)
1 - 14.65 V
all measurements made with the PSU outside the dreambox and not connected to the motherboard
How do you messure the Volts when PSU in the dreambox and connected to the motherboard ?
Are their measuring points for pin 3 to 13 ?
Ok here are the Volt measurements PSU connected to the MB:
Box booted to #84 dhcp.... in display
Pin - V
1 - 14.87 - 14V
3 - 6.76 - 6.4V
4 - 3,27 - 3.3V
5 - 12.14 - 12V
6 - 12.14 - 12V
8 - 5.09 - 5V
10 - 3.36 - 3.3V
12 - 0.04 - 2.5V
13 - 0.04 - 2.5V
Big difference on Pin 12 + 13
Question, How do you messure the Volts when PSU in the dreambox and connected to the motherboard ?
By adding 3.3V to pin 4, For more about this see here, Testing the DM8000HD psu without the motherboard.
Question, Big difference on Pin 12 + 13
12 - 0.04 - 2.5V
13 - 0.04 - 2.5V
This could be related to the C109 22uF 50v cap, see this topic with also the 2.5v issue.
Thank you for your reply.
The differences in Ohm are they due to the ETXEZ654M7F version I have?
The ohm differences could be due the different type psu you have, than the ones I had.
This could happen when the psu has other parts, or another way of build circuits, but also when the psu is used for a while, or some caps where not fully unloaded.
For accurate values must the psu be the same type as the noted values.
In any case, I see no real issues in your ohm measurements, however the pin 10 - 3.05 - (31.07K) which is from the 3.3v circuit is a bit suspicious which could be caused due a bad cap.
To come back to your psu and the ohm measurements.
The psu you have is the type 25x10 Panasonic ETXEZ654M7F psu.
And so, the 25x10 ohm measurements from your psu should be in range of my barcode 25x10 measurements as this..
Yours - (mine values new psu)
1 - 8.57 - (8.54K)
3 - 8.8 - (58.5K)
4 - 9.68 kOhm - (10.09K)
5 - 17,50 - (16.39K)
6 - 17.50 - (16.39K)
8 - 9.05 - (8.93K)
10 - 3.05 - (33.79K)
12 - 8.24 - (8.08K)
13 - 8.24 - (8.08K)
Nevertheless, the situation stays the same, the pin 10 - 3.05 - (33.79K) which is from the 3.3v circuit is a bit suspicious which could be caused due a bad cap.
If you have measured this pin correctly.
I recently (1year) replaced all caps of the PSU, without the 2 very big oned on the hot side.
I will order a capacity meter to check the caps.
Do you have a hint for a good not too expensive one?
What about these 10€ things called LCR-T4?
I have the colored display version, called the Multi-function tester - T7
But (I think) has further the same electronics as these and they works quite good for that value.
But still, even if it indicates that a cap is good, it may not work properly in the circuit
The importance of a good cap is especially important for sensitive frequency-related circuits.
That's the one of the DM7020s / DM7020si, the one on the link, so the old DM7020 SD box.
Here we have the DM8000HD and DM7020HD that both use the same PSU, as the DM7025+ also (but not the DM7025).
Johnny, I have a DM8000HD Original PSU that has some problems that looks like near to these, and I though to change the 22uF/50V (C109) due to the behavior... but probably I will get you it so you can do further tests as it seems working but it doesn't work properly.
No problem,that is, I have no longer a fully working dm8000hd for testing it fully.
Only one board which the internal tuners are death and no longer reparable, only the external tuners can be tested with it.