imac early 2008 el capitan booting problem

Hi everyone.

I need some help.

A few days ago during use, my mac hung itself. Force quit did not work so i needed to shut it down on the power key. From that point on i cannot get it boot up again other than in safe boot. i believe i tried every thing and ran out of ideas. So i hope that someone has a solution.

I started it with cmd r and ran first aid. No problem.

I started it with option cmd p r

I ran apple hardware test no problem.

I cleared Cache

I repaired disk permissions

I re-installed os el capitan

I erased the disk and re-installed el capitan

I changed the disk with a new one and installed os mavericks

I updated os mavericks to el capitan

All four led lights are switched on the logic board when i press the power key.

The battery on the logic board has 3V.

Etrecheck reports no obvious problem. Here is the copy of the report.

Hardware Information:

 iMac (2008) - Obsolete!

 iMac Model: iMac8,1

1 2,66 GHz Intel Core 2 Duo (Duo) CPU: 2-core

4 GB RAM - At maximum

BANK 0/DIMM0 - 2 GB DDR2 SDRAM 800  ok

BANK 1/DIMM1 - 2 GB DDR2 SDRAM 800  ok

Video Information:

ATI Radeon HD 2600 Pro - VRAM: 256 MB

 iMac 1680 x 1050

Drives:

disk0 - CT480BX500SSD1 480.10 GB (Solid State - TRIM: No)

Internal SATA 3 Gigabit Serial ATA

disk0s1 - EFI (MS-DOS FAT32) [EFI] 210 MB

disk0s2 - Macintosh HD (Journaled HFS+) 479.24 GB (12.62 GB used)

disk0s3 - Recovery HD (Journaled HFS+) [Recovery] 650 MB

Mounted Volumes:

disk0s2 - Macintosh HD 479.24 GB (466.36 GB free)

Journaled HFS+

Mount point: /

Network:

Interface en0: Ethernet

Interface fw0: FireWire

Interface en1: Wi-Fi

802.11 a/b/g/n

Interface en2: Bluetooth PAN

System Software:

OS X El Capitan 10.11.6 (15G22010) 

Time since boot: Less than an hour

Safe Mode: Enabled

Notifications:

Notifications not available without Full Drive Access.

Security:

Gatekeeper: Enabled

System Integrity Protection: Enabled

System Launch Agents:

[Not Loaded] 7 Apple tasks

[Loaded] 168 Apple tasks

[Running] 65 Apple tasks

System Launch Daemons:

[Not Loaded] 47 Apple tasks

[Loaded] 161 Apple tasks

[Running] 82 Apple tasks

[Other] 2 Apple tasks

Launch Daemons:

[Not Loaded] com.apple.installer.osmessagetracing.plist (Apple - installed 2018-06-29)

Internet Plug-ins:

Default Browser: 601 (Apple - installed 2016-07-09)

Audio Plug-ins:

BluetoothAudioPlugIn: 4.4.6 (Apple - installed 2019-06-27)

AirPlay: 2.0 (Apple - installed 2019-06-27)

AppleAVBAudio: 406.1 (Apple - installed 2019-06-27)

iSightAudio: 7.7.3 (Apple - installed 2019-06-27)

Time Machine:

Time Machine Not Configured!

Performance:

System Load: 5.15 (1 min ago) 2.86 (5 min ago) 2.67 (15 min ago)

Nominal I/O speed: 12.30 MB/s

File system: 47.80 seconds

Write speed:  239 MB/s

Read speed:  270 MB/s

CPU Usage Snapshot:

Type Overall

System 2 %

User 14 %

Idle 84 %

Top Processes Snapshot by CPU:

Process (count) CPU (Source - Location)

EtreCheck 24.58 % (App Store)

Other processes 7.37 % (?)

Dock 0.03 % (Apple)

cloudd 0.01 % (Apple)

sharingd 0.01 % (Apple)

Top Processes Snapshot by Memory:

Process (count) RAM usage (Source - Location)

EtreCheck 286 MB (App Store)

Finder 73 MB (Apple)

Spotlight 71 MB (Apple)

Safari 66 MB (Apple)

iconservicesagent 37 MB (Apple)

Virtual Memory Information:

Physical RAM: 4 GB

Free RAM: 192 MB

Used RAM: 2.30 GB

Cached files: 1.51 GB

Available RAM: 1.70 GB

Swap Used: 94 MB

Software Installs (past 30 days):

Install Date Name (Version)

2019-06-27 Security Update 2016-004 (10.9.5)

2019-06-27 EtreCheck (5.2)

2019-06-27 Security Update 2018-004 (10.11.6)

2019-06-27 iTunes (12.8.2)

2019-06-27 Safari (11.1.2)

2019-06-27 XProtectPlistConfigData (2103)

2019-06-27 MRTConfigData (1.42)

2019-06-27 Gatekeeper Configuration Data (170)

Diagnostics Information (past 7 days):

Directory /Library/Logs/DiagnosticReports is not accessible.

 Enable Full Drive Access to see more information.

Thank you in advance for any sort of help