The Slow Network Issue
The Problem:
The DM500 is not particulary famous for it's recording and playback abilities on an
external mounted harddisk so don't expect miracles. But this doesn't mean it isn't
possible to record and playback your favorite show. Always bare in mind that sending
a high bitrate DVB stream over your network places a high demand on your network infrastructure.
This has to be in a perfect condition for recording to work as suspected.
A lot of users reported problems with network troughput, resulting in visible artefacts and crippeled
playback and recording. Most of these issues have to do with bad network cabling, bad HUB's or
network switches, slow external harddisk/PC's/NAS/SAN Arrays etc.
Also important are the buffer settings, the used network protocols (i.e. SAMBA, CIFS, NFS etc.),
and the used image.
The forums are full of possible solutions, and I advice to try these solutions first, before opening
the case of your dreambox. 90% of these problems dissappear after correct software tweaking and tuning.
How to do this is outside of this documents scope. Please refer to the sattelite forums for more information
on these
subjects
The remaining 10% has a problem.
And lucky you there is a fix

The Cause:
The DM500 is equipped with a 10/100MBit ethernet interface. This interface consists of 1 chip on the
mainboard
and a couple of surrounding components. (on the bottom left hand of the board).
This chip handles the network connection, and (low level) traffic management. Mostly this is an ASIX
AX88796.
This chip needs the surrounding components to function correctly.
Recently a discovery was made that 3 surrounding capacitors did not quite meet the specifications given
by the manufacturer
of the network chip.
First of all there is a capacitor of 33uF/16V just above the chip (on the right side). This capacitor serves as
a current buffer
for the ASIX and makes sure that sudden short high current demands can be handled propertly, without
the voltage dropping
too low for this chip to operate. You have to understand that network cabling can be very long, so it takes
a lot of energy to
send a signal over these wires. If this energy cannot be delivered in a very short time, network problems
can arrise.
The discoverer of this mod found a value of 220uF/16v (Low Impedance/ESR!) better then the standard
33uF. With a bigger buffer,
the chance of power problems are minimized. I totally agree with him.
Then there are 2 VERY SMALL SMD capacitors just above the network chip. The function of these
capacitors is not totally clear to me,
but also have to do with delivering sufficient energy to the network. Luckely these SMD capacitors can
stay in place, and only need a
'backpack' of 2 parallel capacitors.
The Solution:
- Replace capacitor C65 (33uF/16V) (the 'big' one) by a 220uF/16V Low Impedance/ESR type.
- Solder a 4,7 uF/16V TENTAL! capacitor in parallel with C17. Watch the polarisation!
- Solder a 4,7 uF/16V TENTAL! capacitor in parallel with C23. Watch the polarisation!
Use a temperature of about 350 degrees celcius, and a very small tip! Especially C17 an C23 are very
small!
Below a picture with polarisation of a 4,7 uF Tental capacitor.
Replace by a 220uF/16V
Low Impadance/ESR
Parallel solder the 4,7uF/16V tental
capacitors on top of these two.
When you have done this correctly, the mod will look something like this:
References:
http://www.sat4all.com
http://www.pli-images.org
http://www.siennacountach.net/gallery/dreambox
http://www.dreamboxonline.com/forums...ead.php?t=1983
http://www.siennacountach.net/media/LAN_DM500.pdf
asa am scapat de problema cu Lan-ul
Multumesc userului guzy ptr link
Nu incercati modificarea daca nu aveti cunostinte minime in electronica si lipire smd.
P.S. se pot folosi condesatori obisnuiti ,nu musai cu tantal ,intrucat condesatorii cu tantal se gsesc mai greu.
Inlocuirea integratului nu va duce la eliminarea defectului
Stau la dispozitie tuturor ce au aceasta problema cu receptorul!